Polyurethane film for heat applied graphics

Abstract

A composite film of two layers, comprising a graphic color layer containing at least 50 wt % thermoplastic polyurethane, at least 10 wt % pigment, and a polyester elastomer, and an adhesive layer containing a thermoplastic adhesive. The color layer contains a non-blooming internal wax lubricant constituting less than about 0.1 wt % of the color layer. A combination comprising a laminate of two layers, one layer of which contains a polyurethane and the other layer of which includes an amorphous polyester directly adhered to a fabric, the improvement comprising said layer which contains a polyurethane, having an opaque exposed surface substantially free of surface lubricants. In a process for extruding polyurethane film, the improvement comprising mixing no more than about 0.1 wt % of a non-blooming internal wax lubricant in the polyurethane, prior to extrusion.

I claim: 
     
       1. A composite film of two layers, comprising: a graphic color layer containing at least 50 wt % thermoplastic polyurethane, at least 10 wt % pigment, and a polyester elastomer; and   an adhesive layer containing a thermoplastic adhesive.   
     
     
       2. The film of claim 1, wherein the color layer comprises at least 60 wt % polyurethane and said polyurethane, pigment, and polyester elastomer are distributed uniformly throughout said color layer. 
     
     
       3. The film of claim 1, wherein the polyester elastomer is a block co-polymer comprising a crystalline segment of polybutylene terethalate and an amorphous segment based on long-chain polyether glycols. 
     
     
       4. The film of claim 1, wherein the polyester elastomer contains hard segments derived from a low molecular weight diol and soft segments derived from a polyoxyalkylene diol. 
     
     
       5. The film of claim 1, wherein said color layer contains up to about 70 wt % polyurethane having a higher rate of re-crystallization than the polyurethane sold by Deerfield Urethane as Deerfield No. 8010. 
     
     
       6. The film of claim 1, wherein the color layer contains between 15-20 wt % pigment. 
     
     
       7. The film of claim 1, wherein the color layer has a melt temperature at least about 50° F. higher than the melt temperature of the adhesive layer. 
     
     
       8. The film of claim 1, wherein the adhesive layer comprises one of a group of materials consisting of an amorphous polyester, polyurethane, polyamide, or a combination thereof. 
     
     
       9. The film of claim 1, wherein the color layer contains a non-blooming internal wax lubricant constituting less than about 0.1 wt % of the color layer. 
     
     
       10. The film of claim 5, wherein the color layer comprises 60-75 wt % polyurethane, and 10-20 wt % polyester elastomer. 
     
     
       11. The film of claim 10, wherein the color layer contains between 15-20 wt % pigment. 
     
     
       12. The film of claim 5, wherein the color layer contains a non-blooming internal wax lubricant constituting less than about 0.1 wt % of the color layer. 
     
     
       13. The film of claim 1, wherein the adhesive layer is amorphous polyester. 
     
     
       14. A composite film of two layers, comprising: a graphic color layer containing at least about 60 wt % thermoplastic urethane, a polyester elastomer, and at least about 15% pigment; and   an adhesive layer containing a thermoplastic adhesive having a melt temperature at least about 50° F. lower than the melt temperature of the color layer.   
     
     
       15. The film of claim 14, wherein said thermoplastic urethane comprises a mixture of a first polyurethane material having a melt temperature in the range of about 350° F.-375° F. and a second polyurethane material having a melt temperature in the range of about 345° F.-365° F., and wherein said color layer has a melt temperature in the range of about 330° F.-355° F. 
     
     
       16. The film of claim 15, wherein the weight per cent ratio of said first polyurethane material to said second polyurethane material, is about 2.5:1. 
     
     
       17. A combination comprising a laminate of two layers, one layer of which contains a polyurethane and the other layer of which includes an amorphous polyester directly adhered to a fabric, the improvement comprising said layer which contains a polyurethane, having a substantially uniform distribution of polyester elastomer and an opaque exposed surface substantially free of surface lubricants. 
     
     
       18. A laminate of two films, at least one of the films containing a thermoplastic polyurethane and one film containing a thermoplastic polyester, said thermoplastic polyester being amorphous, and wherein said laminate is non-curling, the improvement comprising said film containing a thermoplastic polyurethane, also containing a substantially uniform distribution of polyester elastomer and a substantially uniform distribution of a non-blooming internal wax lubricant constituting less than 0.1 wt % of the weight of said film.